The present invention relates broadly to a cable attachment technique, and in particular to a direct cable attachment method for attaching ribbon cable directly to either a single chip or a stack of integrated circuit chips.
In the prior art, there are many electronic circuit applications that require multiple connections to either a single integrated circuit unit or a plurality of IC units that are arranged in a stack. An example of such a stack of IC units may be photo-detector array module which is comprised of a stack of semiconductor chips having integrated circuitry on each chip. Presently, it is common practice to connect the electronic circuitry on the back plane of such an IC unit to the balance of the external electronics that would be necessary to provide the operation for the photo-detecting application, by means of a ribbon cable.
Exemplary in the art of attaching cables and leads to circuit boards and integrated circuit chips are the following U.S. patents, which are incorporated herein by reference:
U.S. Pat. No. 3,444,347 issued to Mulcahy on May 13, 1969; PA0 U.S. Pat. No 3,751,801 issued to Praeger et al on Aug. 14, 1973; PA0 U.S. Pat. No. 4,091,529 issued to Zaleckas on May 30, 1978; PA0 U.S. Pat. No. 4,342,152 issued to Taylor on Aug. 3, 1982.
U.S.Pat. No. 4,171,477 issued to Funari on Oct. 16, 1979;
U.S. Pat. No. 4,337,573 issued to Nicholas et al on July 6, 1982;
Praeger et al reference is an example of the field of art with its disclosure of a miniature ribbon cable 12 having its conductors 14 soldered directly to the contacts 16 that are carried on a connector plate 18. The patent states that the connector plate 18 may be a dielectric circuit board. In the Praeger et al patent, the cable conductor ends are attached and electrically connected to the circuit board contacts by reflow soldering. Both are pretinned and heated with infrared energy.
The Taylor reference shows a method of terminating and connecting flat ribbon cables. A reflow soldering technique is taught in the Mulcahy patent.
Micro-surface welding is disclosed by the Funari reference wherein a pair of electrically conducting bonding tip members which are spaced from each other, are utilized to achieve the connection. Electrical interconnection using welding techniques is also taught by Nicolas et al reference.
The Zaleckas patent discloses the technique of bonding beam leads to the conductive gold pattern 15 on a dielectric substrate 12. The pattern may connect to one or more integrated circuit chips 16. However, none of the cited patent references show a ribbon cable to chip stack direct bonding system that utilized epoxy for additional support and strength. The present invention is intended to satisfy that need.